A new method for producing high quality, water-based conductive graphene inks with high concentrations has been developed by researchers from the Graphene Flagship.
The novel method uses ultrahigh shear forces in a microfluidisation process to exfoliate graphene flakes from graphite. The process converts 100% of the starting graphite material into usable flakes for conductive inks, avoiding the need for centrifugation and reducing the time taken to produce a usable ink.
The inks produced by the microfluidisation process have high concentrations of up to 100 grammes of graphene flakes per litre and can be optimised for screen printing. These inks can also be used to create novel composites, coatings and energy storage devices.
Dr Panagiotis Karagiannidis, a researcher at the Cambridge Graphene Centre and lead author of the work, said: “The motivation was the need for layers with low sheet resistance to be produced by screen printing using inks with high concentration.
“In the microfluidisation process, all of the starting mixture experiences the same uniform intensive shear levels, converting it into a usable ink with high concentration. There is no wastage of material or time consuming post-processing.”
Professor Andrea Ferrari, director of the Cambridge Graphene Centre, said: “This is an important conceptual advance, and will significantly help the innovation and industrialisation goals of the Graphene Flagship. The fact that the process is already licensed and commercialised indicates how it is feasible to cut the time from lab to market, even during the lifetime of the Flagship.”
The research is published in ACS Nano.